John william nunns



UNITED STATES PATENT OFFICE,

JOHN VLLIIAM NUNNS, OF NEW YORK, N. Y.

cAN'vAs-STRETCHER.

sPEcIFIcA'rIo forming part of Letters Patent No. 602,858, aatea April 1'2, 1898. Application filed July 1, 1897. Serial No. 64:8 ,162. (No model.)

To all wiz/0m it may concern:

Be it known that I, JOHN WILLIAM N UNNs, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Stretcher-Frames; and I do hereby declare the following to bea full, clear, and exact description of theinvention, such as will enable others skilled in the art to which it appertains to 7make anduse the same.

This invention relates to stretoher-frames such as are used by artists and others, on which canvas or similar material is stretched to put it under requisite tension for applying oilcolors thereto.

Stretcher-frames as heretofore constructed and such as are now in general use are made either with mortise-and-tenon corner-joints or with miter-joints. The former are keyed with wooden wedges, and the latter are held together by a metallic plate provided with a wedge which is adapted to enter the miterjoint and thus force the Sections ofthe frame apart to put the canvas under tension. Each of these constructions presents objections.

In the mortised-and-tenoned frame thewooden i wedges shrink and fall out and in the mitered frame the wedges Operating in the joints move two parts of the stretcher-frame at the same time, which is often unnecessary and sometimes results in throwing the stretcher-frame out of true.

It is the object of this invention to overcome these objectionable features and to provide a corner-key for a stretcher-frame which will hold the stretcher-frame firmly together and at the same time stretch only one of its sides independently of the others. I attain these objects by the device shown in the accompanying drawings, in which- Figure 1 is a view in perspective of the rear portion of a frame in which the parts of the frame are provided with miter-joints, showing two of the keys in position thereon and two different ways of securing the same in position and showing, further, the grooves in the two parts of the frame which are adapted to be engaged by tongues on the under side of the key. Fig. 2 is a viewtin perspective of the bottom or under side of the key. Fig. 3

is a similar view of the top or upper side of the k'ey. Figs. 4 and 5 are perspective views showing, respectively, the upper and under sides of a key struck up from a single piece of metal. Fig. 6 is a View in plan of a modified form of key.

Referring to the drawings, A designates a frame, the corners of which in this instance' are assembled with miter-joints, although it is to be understood that mortise-and-tenon joints may be employed, if preferred. 'Secured at each corner of the rear side of this frame is a key B. This key is constructed in such manner that when operated it moves along in a line parallel with a side and end of the stretcher-frame, 'and these two movements are attained, first, by providing the key at its under side and along its inner edge with a flange b, which laps the inner sides of a stretcher-frame at the corners and parallel thereto, forming a right angle, as shown in Fig. 2, and, second, by two ribs 192, likewise attached to the under side of the plate approximately midway between` its inner and outer edges, one on each side and parallel with the sides of the flange b and with the sides of the stretcher-frame, as shown in Fig. 2. These ribs are beveled or wedge-shaped in cross-section, and when the key is adjusted they are pressed into appropriate grooves a, Fig. 1, which eXtend parallel with the sides of two parts of the frame and at right an gles to each other and give the key a firm hold on the stretcher-frame.

The key is held to the stretcher-frame by screws C, as shown at the upper right-hand corner of Fig. 1, which pass through slots 113 in the key, said slots extending parallel with the ribs 62, or the key may be held in place upon the frame by staples D, as shown at the lower left-hand corner of Fig. 1. Inaddition to the slots bS the key is provided with two other slots 64, which merge into the opening b5, these' openings being designed, primarily, to li ghten the key; but they are also intended to be utilized to accommodate ,additional screws if it should be required to give the key a firmer hold on the frame. At each corner of the flange b and on the outer side of the key there'are formed two projections b, which are designed to present surfaces to be struck When the key is to be moved in one direction or the other.

The form of key described is east of a single piece of metal; but in some instances I may prefer to strike the key up from a piece of sheet met-al, as shown in Figs. 4 and 5. To accomplish this, a rectangular piece of metal will be employed, and the same is split from one corner inward toward the center to permit of the metal freed by this slit being' turned at right angles to the body of the plate, as shown at E, to form a flange corresponding` with the flange Z) in Fig. 1, a portion of the metal of each of these flanges being,` stamped out to form projections e, which correspond to the projections bfiin Figs. 1, 2, and 3. There are also formed the slots 82, corresponding' with the slots bin Fig. 1, the metal stamped out to provide this opening` being formed into a rib 83, corresponding' with the rib Z), Fig. 1. There are also provided the supplemental slots D3, corresponding` to the slots b' in Fig. 1, and slots 85 in the flanges E, these la-tter slots being adapted to receive serews or nails for holding these flanges close against the frame.

In Fig. G I have shown a slight-ly-modilied form of key wherein the ribs D2 are (lispensed with. In all other essentials the key illustrated in this figure is the same as that shown in Ifigs. 2 and 3. This key maybe used in connection with smaller frames where the Canvas will not bo so dillicult to stretch tight and therefore obviates the necessity of employing the grooves o in the frame.

When the frame is assembled with these keys in place and it is d esired to tighten the eanvas on one side or end, the projeotion b or the flange b is struek with a suitable tool to force the Sections of the frame apart, after which by tightening either one of the other screws O the frame will be held in its adjusted position.

Having' thus fully described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is-

1. A stretcher-key comprising a Inetallic plate provided with a right-angled, inturned flange, and with slots extending parallel With the fiang'e, and-ribs extending parallel with the slots, substantially as deseribed.

2. The combination with a frame provided, at its corners, with grooves, of a key comprising a metallic plate provided with a rightang'led, intnrned flange, to bear against the inner walls of a corner of the frame, and with slots extending parallel with the flange, two ribs extending parallel with the slots for engaging' the said grooves, and screws passed through the slots, substantially as deseribed.

In testimony Whereof I aflix my signature in presence of two Witnesses.

JOIIN VILLIAM NUNNS.

litnesses:

IIENRY BOHMER, HARRY M. CHURCH. 

